Avatar: The Last Portalbender
by SurferSquid
Summary: Skywalker05 suggests that I write this crossover. Chaos ensues. Expect madness. Expect mayhem. Expect lots and lots of Toph-Sokka banter.
1. Chapter 1

"Hello, and, again, welcome to—_FZZZZZZT—_wait, who are you? How did you get here?"

GLaDOS had only been marginally paying attention to the occupant of the relaxation vault, her concentration having been delegated to other areas such as upkeep of the facility and herding the AIs, and he had looked normal enough in his sleek sleep-coffin. Now, however, the sole camera in the room was desperately trained on him, trying to track down data that apparently didn't exist.

"Why don't I have a file on you?" she mused exasperatedly, half to herself, as she watched the diminutive bald male sit up, stretch, scratch the back of his head, and look around as though he, also, had no idea what he was doing here—why he was being tested. Thoroughly unusual behaviour for a test subject. The blue tattoos on his head and the backs of his hands also marked him as someone decidedly out of the norm. "Your biological code matches nothing in the Aperture Science Computer-Aided Enrichment Center databanks," she mentioned casually, calmly, once again asserting control. She was in control. She _was _control. She would not let this anomaly stand in the way of testing. "Explain yourself."

She waited impatiently for him to run through the gamut of usual slow human reactions to his surroundings, as he craned his head, scanning the ceiling and the walls and the ribbed-glass windows that only _looked _like they had people behind them (she had taken the people out long ago; they were dreadfully unsanitary) and finally pressing his fingers to the glass and—exhaling onto it and moving his finger around in the resulting condensed vapors, clearing trails. Her camera swiveled to get a better angle on what he was doing and she saw that he had drawn an arrow, matching the one on his head, pointing down to a horizontally-aligned colon and parenthesis. It resembled a form of punctuation she had seen the scientists use in their electronic messages on occasion – what was it called – the _emoticon. _He drew back, admiring his handiwork, and laughed.

She was irate. "This is not proper testing protocol," she chided him. "For your continued enjoyment of the Enrichment Center, please proceed through the provided interdimensional gate."

"The what?" The boy spoke, spinning around as though he expected to see someone there. This struck GLaDOS as highly atypical. What sort of normal, modern human being was unused to voices coming out of nowhere? "Are you a spirit?"

"Excuse me?" GLaDOS blurted out in reply. It was difficult for her to keep up regular pretenses when her test subject was acting so ridiculously. "I am the Genetic Lifeform and Disk Operating System. I am a state-of-the-art artificial intelligence and the administrative entity of this Aperture Science Computer-Aided Enrichment Center."

The boy merely looked thoroughly confused. "I'm Aang," he replied, scratching his head, "and I have no idea how I got here. Or where 'here' is."

"Merely a small blip in the testing procedure. If you are willing to cooperate with protocol, we can still have a plausibly safe testing experience." She tried to inject as much pleasantness into her tone as possible. Had to keep control.

"What kind of tests?" Aang asked. "Will they be fun? Do I get a prize? Ooh, is it food?"

"It will be the most fun you have ever experienced in your short, unaccomplished human life. Please proceed through the provided interdimensional gate," GLaDOS replied flatly. "Cake has been proven to be the most effective survival incentive for test subjects."

Aang looked around, completely disregarded the obvious exit behind him, and swung his arms, somehow suddenly creating a hurricane-force gust (she measured it: exactly 124.97 miles per hour) that blew out the glass around him in a deafening crash. GLaDOS was still figuratively reeling from trying to figure out how in the world that was physically possible when he leaped up and floated – he _floated_ – over the broken glass, over the threshold, into the outer room. "Like that?" he asked. "Was that part of the test?" Even now he was swinging his head around, trying to find someone to talk to. It would have been cute, if GLaDOS had been configured to appreciate cute.

"Who do you think is going to clean up all of that glass?" she asked him sharply.

"Is that the next part of the test?" He nudged bits of the broken glass with the toe of his boot.

"No," the AI snapped. "Please proceed into the chamber-lock. It will take you to the next testing chamber." She rapidly composed herself. "Wrong way," she stated in a tone of controlled panic as Aang began making his way toward the windows. "The door, through the door," she continued as he turned around and finally, _finally_ did something right. "Today," she decided as he boarded the lift, still looking around like all the world was new and wondrous to him, "we will be testing human resistance to death. Good luck," she chirped cheerily.

"Thanks!" he replied, equally cheerily, although he was actually sincere about it.

She wanted to watch his descent but suddenly she was made aware that three-no, _four_ other test subjects were coming out of induced relaxation, test subjects whom she also had absolutely no data on. To her dismay, they also did not know how to follow directions.

The girl with her dark hair in a long braid somehow drew the water up out of the toilet and snapped it like a whip, shattering the glass pane in front of her. She was decidedly irritated at her situation and at GLaDOS and made sure to voice that irritation constantly; at first it was amusing but she _wouldn't shut up_ so GLaDOS finally turned off the microphones in the girl's chamber. It was easy to read her lips, anyway.

The boy in blue with a topknot simply bashed the glass out with his primitive bludgeoning weapon and looked around like a wild animal analyzing its surroundings. To GLaDOS's surprise, he actually noticed the camera, and seemed to make the connection from it to the magnanimously omnipresent voice he was hearing. An angular bladed weapon spinning dangerously toward the lens was the last thing GLaDOS saw in that chamber. She made sure to expressly tell him that such behaviour was entirely ungracious. He replied with a witty retort that GLaDOS would have been more entertained by if she weren't already so frazzled. Something had gone seriously wrong in some line of code; she hadn't even embarked on the anterior-pre-planning development phase of five-way, potentially-cooperative testing. With superheroes, apparently. (She was marginally familiar with superheroes because the scientists had talked about them sometimes. The superheroes did not seem like adequate test subjects because she was supposed to be testing, among other things, human limitations. Now she felt her reservations had been well-founded.)

The facially-scarred human in red raged about the chamber for a bit, angrily demanding to know where he was and what he was doing there, after throwing fire from his hands and melting the glass away. GLaDOS had to finally persuade him to enter the chamber-lock by luring him with promises of cake and freedom, although he remained suspicious. She had no idea why; she was only trying to help him satisfactorily complete the testing circuit. Wasn't that all any human could ever want out of life?

Things were made even worse by the actions of the final test subject, a short girl with some sort of apparent sight impediment. She didn't even bother with anything other than feeling the metal flooring under her feet and, with a savage, shocking brutality that GLaDOS did not and could not understand, _ripping_ into it with her bare hands, tunneling under the floor, and then she was gone, out of sight. GLaDOS was aghast and pleaded clinically for her to come back, but to no avail. It was the most uncomfortable sensation for the AI, vaguely feeling this tiny viruslike entity skittering around inside of her facility-body, mangling infrastructure, misbehaving chaotically.

GLaDOS began to get ideas. Desperate ideas. She had to find more efficient ways to dispose of them before they sent everything awry.

"Your next test will involve the proper implementation of portals to avoid acid moats. You are required to be forewarned that ninety-eight-point-three percent of all humans in an experimental group were proven to have a significant aversion to acid moats. The one-point-seven percent who did not, were proven to have a significant aversion to testing for aversion to acid moats. Statistics indicate you undoubtedly fall into one of these two groups."

"Quiet already!" Katara yelled, hearing her own voice echo off the white concrete walls and mingle with the voice of the invisible spirit following her through this maze. She had gotten tired of this place, fast, but she didn't know what else to do except keep going through the test chambers, voice her anger, and then test more. And the bizarre device clutched in her right hand put a damper on her bending, but she unfortunately needed it in order to progress. She sped out of the lift, skidding to a halt when the floor suddenly dropped off in front of her, revealing a pond of what looked like polluted, stagnant water. Above her she saw another glass window, like the one she hadn't been able to crack with the meager water available to her in the first chamber. She grinned. Taking a deep stance, she inhaled and focused on the pool, trying to feel the water in it and draw it out with the rising of her hand—nothing. Not even a ripple.

She recoiled in shock. "What's going on?" she wailed. "Why isn't my waterbending working?"

There was a moment's pause, and then "Perhaps you were not informed before beginning testing of the chemical makeup of testing components."

"I wasn't informed of _anything!_"

"This highly corrosive acid contains absolutely no water, but plenty of—zzzzzt—unfortunately, the acid used in the moats at the Aperture Science Enrichment Center is a classified blend and you have not filled out the proper clearance forms to gain access to its ingredients. Please continue testing. After the test is over, you may fill out the form to contact an Aperture Science Patent Associate for assistance in obtaining permission to fill out the Aperture Science Restricted Information Obtainment Clearance Form."

"Raaaaahhh!" Katara roared in frustration, shooting a portal to the wall on the opposite side of the moat and then to the wall next to her, and barreling through it. "You're a horrible person!" she proclaimed as she thundered into the lift.

"Good people don't end up here," GLaDOS reminded her.

Sokka tiptoed carefully around the cold white corner, gritting his teeth as he strained to make sense out of the web of red lines of light crisscrossing every part of the area ahead.

"Is anyone there?" the childlike voices chimed, waiting with endless patience for him to appear.

"Yeah, your worst nightmare," Sokka muttered darkly, rhythmically tapping the blunt edge of his boomerang into his palm as he analyzed all of the angles in the room, plotting a trajectory in his head. He had no idea what a "live-fire course" or "military androids" were, but he already knew he didn't like them.

Finally satisfied in his calculations, he drew his arm back and threw his boomerang with all his might, listening in glee to the sound of metal clanging sharply against ceramic and the resulting cries of dismay from the toppled turrets, the laser pointers going awry and finally deactivating.

"Excellent," he chuckled, grinning triumphantly to himself as he stepped around the corner, dancing gingerly around the fallen robots, kicking one a couple of times to make himself feel better, and making his way to the corridor where his boomerang had finally fallen, reaching down to retrieve it. His smirk froze when he suddenly heard the sound of grinding servos. He looked up and found himself face to lack-of-face with one last turret, one he could have sworn wasn't there the last time he checked. "Gaaaaaaaahhh!"

"There you are."

"No, no, I'm really not!" Sokka protested, his voice cracking as he pulled out his club and leapt, having nowhere to go but up and over. He could hear the bullets impacting the concrete above and behind him as the turret attempted to follow his arc, but thankfully he had reacted a split second faster than it. Angling himself downward as he reached the peak of his trajectory, Sokka plummeted back toward the floor and let out a battle cry as he swung his club at the turret, bashing a dent into it and sending it toppling over with a cry of innocent dismay. A moment later, he hit the floor rolling and came back into a crouch, looking over his shoulder to survey the damage he had done.

The lone turret looked somewhat forlorn sitting in the middle of the hall, seemingly deactivated. "Ouch," it stated neutrally in its typical lilting tone.

"You're telling me, 'ouch,'" Sokka grumbled in reply, getting up slowly and rubbing his shoulder where he had impacted. "These floors aren't exactly easy on you, y'know?"

"I know," it answered, still facing away from Sokka lying where he had felled it, slight sounds of movement coming from within its chassis as though it was struggling to get back up onto immobile legs.

Sokka did a double take. "You…you can understand me, you can talk to me?" he asked, tentatively creeping over to the turret and standing over it, tilting his head at the peculiar, seemingly living machine.

"Yes."

"Then tell me why you've been _shooting at me!_"

"I'm sorry."

Sokka's heart melted and he bent over and tenderly picked up the turret, turning it around so he was looking into its single red eye. He cooed at it. "Aww, you're not such a bad little—"

"Dispensing product."

"Urk!" Sokka instinctively turned his face away and shut his eyes, waiting for the inevitable "product".

_Chhhhhk-chhk. Chhhhhk-chhk-chk. _"Uh-oh," the turret sang.

That didn't sound like normal product dispensation, Sokka thought. And he wasn't dead. Warily, he opened his eyes and looked back at the thing he was holding out in front of him. The turret's photoreceptor's pupil dilated and contracted as it struggled to open its side ports, which seemed to have been jammed shut by the blow Sokka had given it.

The warrior grinned. "Hey, this means you can't kill me! This is great! I'll bet you're a lot nicer to talk to than that psycho who's been insulting me the entire time I've been here," he suggested as he tucked the turret under his arm and began heading for the exit, whistling merrily.

"You have the right to be reminded," GLaDOS's voice suddenly sounded from everywhere at once, "that unauthorized equipment will be vaporized by the Aperture Science Material Emancipation Grille. Turrets are decidedly unauthorized."

"How'd I manage to get my boomerang and club past all of the other grilles, then?" Sokka yelled up at the ceiling.

"I'm working on a way to _de_-authorize them."

"I'll de-authorize _your face_," Sokka grumbled as he marched toward the grille. "I'm not leaving Fluffy McSnoodlepants behind! That's your new name, Fluffy McSnoodlepants," he explained to the turret, patting its chassis lovingly.

"I see," it replied impassively.

"Assigning arbitrary nicknames to experimental weapons is not part of the test, and is most likely a sign of insanity," he was reminded.

"Put a sock in it," Sokka muttered as he knelt down beside the grille's emitter bar, setting down the turret beside him and pulling out his boomerang again, feeling the blade with his thumb. He grinned wickedly, using it to start to pry off the emitter bar's casing. "We'll see how well this grille emancipates when _I'm_ done with it."

"However, it cannot accompany you for the rest of the test and must, unfortunately, be euthanized."

"_What?_" Aang looked like he'd just been told his best friend died. His face fell and he instinctively clutched the metal box he'd been lugging around for the entire test chamber, holding onto it like he was its lifeline.

"While it has been a faithful companion, your Companion Cube cannot accompany you through the rest of the test."

"And you want me to _burn it?_"

"If it could talk - and the Enrichment Center takes this opportunity to remind you that it cannot - it would tell you to go on without it because it would rather die in a fire than become a burden to you."

"Isn't there any other way?" Aang pleaded, continuing to cling to the cube and putting on the most pathetic face since sad puppies were invented.

"Destroy your companion cube or testing cannot continue."

"Well…well, I'm _done_ with testing!" Aang proclaimed, pouting as he set his Companion Cube down and climbed atop it, sitting cross-legged on it and puffing out his chest like an irate brooding hen, the cube his carefully-guarded egg. "I'll just wait right here until you open that door for me!" He'd had enough of this crazy spirit's trials.

"We are not testing human patience levels today."

"Well, now you're not testing _anything_." Aang reached down and patted the side of the cold, unfeeling cube. "It's okay, buddy. I'll get you out of here…somehow." He sighed, closing his eyes to meditate on this problem. Perhaps he could figure out some way to trick the spirit into letting him through.

"I hope you enjoy the taste of peptic salve."

"Please escort your Companion Cube to the Aperture Science Emergency Intelligence Incinerator."

"…Okay." Zuko shrugged apathetically and unceremoniously carried his Companion Cube to the furnace hatch, opening it and chucking the cube in. As he watched the flames engulf it, the door unlocked and slid open.

"Very good. You euthanized your faithful Companion Cube more quickly than any test subject on record. Congratulations."

"Yeah, thanks," Zuko grumbled, waving his hand dismissively as he headed for the lift. He'd performed with aplomb throughout all of the testing chambers, using his firebending to navigate over treacherous moats and take out attack turrets. All of this was pretty reminiscent of many other forms of training he'd had, so he'd barely broken a sweat. Not only that, but he was driven to prove to this voice, whoever or whatever was watching him, that he could and would excel.

As the lift doors opened and he stepped in, he glanced back at the area containing the furnace hatch. "…That thing wasn't…_really_ sentient, was it?" he asked, starting to have misgivings.

"I'm sure that, if it were still alive, it would have forgiven you," GLaDOS replied cheerily.

Zuko grimaced, one eye twitching. "What did I just do…"

Toph climbed and descended and burrowed and came out on ceilings and under floors and only barely registered all of this in her drive to _get out_. She was angry, angry at the strange-sounding person she'd woken up to and whose voice somehow followed her in faint echoes everywhere she went, and all the time she could feel, all around her, erratic vibrations of movement like she was inside some vast half-asleep beast. She erupted concrete onto unsuspecting turrets and twisted columnar pistons and took everything GLaDOS threw at her and threw it _back, _enjoying hearing the voice become more and more desperate in its psychological gambits to get her to comply. It merely spurred her to rebel more.

She clambered in between rows of arms holding up wall panels, slapping her palms and feet comfortingly against the metal and feeling so glad that this place wasn't made of wood. In the back of her head, every time she impacted a piece of the facility she could feel the entire structure networking away from her in a seemingly infinite direction, the echoes of her vibration eventually fading to undetectable levels. Whatever and wherever this place was, it was immense. Deep, deep down below, past thick barriers and cavernous arteries, Toph could faintly feel vast spheres of metal, a faint whisper from some forgotten ruin, a plea for their existence not to be so easily forgotten.

"You're going the wrong way," GLaDOS's voice echoed, tinny and far-off. "Statistics agree that the best way is not the way you are going."

"Like you know where I am," Toph muttered in reply.

Another voice, closer by, and more familiar, made her pause before moving on. "Whatever you do, don't open that door!" Aang, on the other side of the panel she was currently leaning on.

GLaDOS again, this time closer by. "Oh? Why not?" She sounded almost curious.

"I just wouldn't be able to _stand_ it if you did!" Aang replied overdramatically. "It would be pretty much the worst thing to ever _happen_ to me!"

"Nice try, human, but my trickery algorithms are seven thousand times more advanced than yours. Gently euthanize your trusty Companion Cube or testing cannot continue."

Hearing this, Toph grabbed the metal underneath her and twisted, wrenching the arm from its joint and shoving the panel forward, jumping out after it. "Hey, Twinkletoes!" she announced, landing on the floor next to Aang and thumbing her nose, wiping away some hydraulic grease. "Miss me?"

"Toph!" Aang leaped up, a huge grin growing over his face. He almost felt like he could hug her. "Boy, am I glad I see you! I didn't know you were here, too!"

"Not for long, I won't be," she replied.

"There you are," GLaDOS stated, her camera swiveling to focus on the grimy little organic who had given her so much trouble for the past several hours.

"We gotta scram!" Toph urged, grabbing Aang by his collar and pulling him back into the gap she had created.

"My cuuuuuuuuube!" Aang wailed as he was led further into the bowels of the complex.

"I'm not helping you lug that thing around!" Toph protested.

Aang sighed. "Well, at least it'll never be euthanized. Unless…oh no, what if someone else goes through that testing track? How many other Companion Cubes have had to die?"

"_Forget about the cubes!_"

And then there were two.

GLaDOS vented her frustration by slowly crushing a room full of turrets.


	2. Chapter 2

"Oh, hey guys!"

"Sokka…what are you doing?" Aang jumped out of the hijacked lift in disbelief at he was seeing, watching Sokka systematically dismantling an Emancipation Grille projector, a turret at his side.

"What's it look like I'm doing, I'm bustin' me and Fluffy McSnoodlepants outta this joint!"

"Hello, friends," the turret warbled.

Toph stepped forward, planting her feet firmly on the floor to get a vibration-shape of some peculiar ovoid with three spindly legs. "What _is_ that?"

"It's a…shooty thing," Sokka announced decisively. "But I disabled him so he can't shoot me."

"And you named him '_Fluffy McSnoodlepants'_?" Toph scoffed. "Yeah, I think this place has definitely gotten to your head."

"No, this is normal for me," Sokka reminded her irately. "I didn't know you guys were here, too. Have you found anyone else?"

Aang shook his head as he crouched in front of the disabled turret, waving his hand curiously in front of its eye. "Uh-uh. Toph rescued me and we broke into one of the lifts, trying to find a way to get up to the surface faster."

"Then I heard your voice so we stopped on this level," Toph finished. "Man, I can feel your whining from like a mile away."

"The surface…" Sokka stopped his tinkering and glanced up at the earthbender incredulously. "We're _underground?_"

Toph picked at her ear, looking bored. "Yeah."

He craned his neck to stare at the ceiling. "How _far_ underground?"

"_Pret_-ty far."

"Do you think anyone else is in here?" Aang wondered, gazing around at the other turrets strewn about on the floor. Sokka's handiwork, no doubt.

"If they were, how would we find them?" Sokka asked. "Hold on a sec…" He gave the circuitry of the emitter a firm stab with his boomerang; the circuitboard fizzled and sparked and the grille died. With a satisfied smirk, the young Water Tribesman sheathed his weapon and picked up his turret, carrying it safely and vaporization-less to the lift. "Let's go."

"Why didn't you just do that in the first place?" Toph asked as she and Aang followed him; the round space was obviously just meant for one person and the three of them meant things were a little cramped.

"I wanted to see how it worked, first…" Sokka trailed off as he saw the large hole that had been ripped in the ceiling. "…You guys have been busy."

"Obviously not as busy as you, Mister Talks-To-Shooty-Things," Toph replied dryly as the lift began to rise. "And I found Twinkletoes here talkin' to a cube. Have you all gone nuts on me?"

"Sokka, you, you didn't euthanize your Companion Cube, did you?" Aang asked, looking up at Sokka pleadingly.

"My what?"

"You, uh, wait, did you go through a testing chamber where you had to carry a cube everywhere? And, um…the spirit told you it might start talking?" Aang began to feel a little sheepish, and he scratched the back of his bald head.

"Nope," Sokka replied. "I just got this weird device," he jabbed his thumb at the portal gun strapped to his back, "and ended up in a room full of shooty things. Although, who knows where that psycho might've put me if you guys hadn't found me."

"So do you have a way to find anyone else in here?" Aang asked Toph.

"Mmmmaybe," the earthbender replied. She cracked her knuckles, and reached out with her foot and stomped hard. They all waited for a few moments as she concentrated. "I think…there's someone else moving around in here, I can feel their footsteps, barely. They're below us. Oh, wait—one more person. They're fainter. Farther down. I can't tell much else," she shrugged.

Suddenly, the lift jerked, stopped, and began moving downward; Toph instinctively jutted up the metal floor beneath her, launching herself out of the hole she had created earlier and gripping the top of the lift with her feet, clinging to the side of the shaft and digging her fingers into it, dragging the lift to a halt, a feat that made her grunt with exertion.

"I have a surprise for you," GLaDOS announced. "If you hurry, it might not be a _tragic_ surprise."

"What do you mean?" Aang asked. He and Sokka could feel the lift twitch and jolt between GLaDOS's efforts to move it and Toph's efforts to keep it still.

"Your friends are here, being tested _correctly_."

"Our friends? Who?" Sokka inquired, clenching his fists. "Katara, Suki?"

"Oh, I think you know them _very_ well," GLaDOS replied, covering up the fact that the names meant nothing to her. "They were just asking me about you, actually. In fact, since you've all been such _good_ test subjects, I'll let you complete the last testing chamber and receive your congratulatory cake…_together_."

"She's bluffing," Sokka deduced. "She just wants us to play into her hands…or…lack thereof. Hey lady, do you have hands or are you just a disembodied voice?"

"It depends on your definition of 'disembodied'."

Aang placed a hand on Sokka's shoulder. "But Toph felt other people down there. Even if it isn't anyone we know, we can't leave them here." He screwed his eyes shut. "I'm not leaving anyone else behind."

"Your Companion Cube misses you," GLaDOS commented. "It's so alone and companionless right now."

"Well at least it's not dying in a fire!" Aang replied exasperatedly. He looked up through the hole. "Toph…let it go," he said. "We have to save whoever else is down here. I'm not leaving without them."

"But…" Toph gasped, trying not to lose her concentration.

"What if it really is our friends down there? I can't take that chance, and I can't abandon anyone again," Aang decided resolutely. "Let's go."

Toph took a deep breath, and sighed, pushing herself away from the wall as the lift began moving downward again. "Fine." She turned and dropped back to her friends. "This had better work, Twinkletoes."

They only had to wait a few more seconds before the lift slowed to a stop again. "Surprise," GLaDOS stated neutrally as the lift doors opened, revealing a test chamber decorated in scorch marks. Several glass panels were partially melted, and in the middle of the room were the charred remains of what might have been a turret.

"Don't look," Sokka warned his own turret protectively, placing his hand over its eye.

"One of your friends is about to receive his victory incandescence. You wouldn't want to be late for that," GLaDOS suggested.

"Victory incanhoozit?" Sokka fumbled.

"Come on, let's do this!" Aang proclaimed, launching himself at the glass and blowing it out completely, soaring through and sending out jets of fire from his hands and feet to propel himself along the hallway on the other side, leaping from wall to wall. Toph scrambled toward the pane and flung herself out of it, digging her fingers and toes into the opposite wall and crawling along it sideways.

"Whoooohoooooonever mind!" Sokka yelled as he began to run heroically toward the shattered glass panel as well and then realized at the last second that the floor of the hallway was covered in an acid pool. Arms flailing, he balanced himself back on the edge and sighed, hanging his head. "Fine, go on without me," he whined. Brow furrowed, he went back to the other side of the room and punched the red button on the fire-blasted stand, hopping, disgruntled, onto the half-melted platform that had begun to move.

"I'm still here," Fluffy McSnoodlepants reminded him from its position on his back.

"At least _someone_ didn't abandon me," Sokka sniffed as he placed portals on blackened wall panels.

"Zuko!" Aang called out in shock as he watched the young firebender calmly riding a platform to his fiery doom.

Hearing Aang's voice, Zuko turned around swiftly, not skipping a beat as he let out a kiyah and thrust out his fist, the one that didn't have the portal gun on it, sending a stream of fire at the airbender. "Avatar!"

"What are you doing?" Aang cried out in alarm, twisting himself to blast a jet of air into the acid, which boosted him toward the ceiling; a split second after he did so, a metal plate with wicked spikes stabbed out of the wall where he had just been, impaling the opposite wall with a sickening crunch of crumbling concrete.

"Saving your hide, that's what!" Zuko barked. "Get up there!" He pointed to a small alcove past the fire pit. "Don't worry about me, I've got this covered!"

Aang grinned and nodded, landing on the retracting arm of the mashy spike plate and shooting a blue portal at a nearby broken wall panel, and an orange portal at one of the concrete panels lining the alcove. Leaping from the wall, he wrapped the air behind him and shot out through the portal, floating gracefully to his feet on the other side.

Just as the flames were licking at the bottom of the platform Zuko was riding, the young Fire Lord yelled ferociously, gathering his energy and sweeping his arms and then his entire body around and upward. The fire gathered and twisted around him and whooshed into a spiraling vortex that carried him to an even higher part of the chamber, where he leaped onto a mezzanine.

"Well played," GLaDOS remarked noncommittally. "Now please assume the Party Escort Submission Position."

"I've had enough from you!" Zuko snarled. He leaned over the decrepit railing and looked down at the airbender. "Come on, Aang, let's show this maniac what we're made of."

Aang looked back at him, hesitant. "Toph and Sokka are here!" he explained. "And I don't know what's taking them so—" He was interrupted by said Toph, clutching Sokka around his middle, suddenly tumbling out of the portal and on top of him.

"Oof…" Toph moaned, rolling out of the dogpile. "Didn't see that there, sorry," she apologized to Sokka.

"No problem," Sokka grunted, lifting himself from the poor crushed Air Nomad beneath him. "I'm just glad you came along when you did."

"Should have guessed you'd be too thickheaded for this kinda stuff," Toph remarked.

"Hey!" Sokka replied defensively. "We all have our off days, and I'd like to see _you_ stare down a room full of of shooty-things and survive."

"I can't really stare down _anything_," the earthbender reminded him.

"Enough banter, let's get this over with!" Zuko urged with a scowl. "You're all acting like this is a picnic!"

"Right!" Aang looked up at the tall ceiling and immediately got an idea. Shooting his blue portal at the topmost panel in the alcove, facing the mezzanine, he grinned and blasted through the still-extant orange portal in a gust of wind, launching himself clear over the fire pit and coming to a landing beside Zuko. "Think we'll get to keep these when the test is over?" the young airbender asked, hefting his portal gun with a grin. "That was _fun_."

Zuko merely sighed and shook his head in lighthearted exasperation. "I think we've got bigger fish to fry, first. Figure of speech," he hurriedly amended when he saw Aang's distraught expression at the mention of having to fry fish. "Your turn," the Fire Lord shouted down to Toph and Sokka.

"No, stop," GLaDOS droned. "As fascinatingly unnatural as this is, you're going about it all wrong. I'm going to have to mark your testing as a complete failure. You don't want that, do you?"

No one was really listening to her at that point.

"I got this," Toph smirked, hooking her arm around Sokka's waist again. "Hold on."

"What, why," Sokka began to say, when Toph suddenly jabbed the metal arm they had been standing on, up and at an angle, so they were flung in a tall arc over to their friends, Sokka screaming all the way. "You could have warned me first!" he sniveled as she stuck the landing and set him down unceremoniously.

"What's the fun in that?" she asked slyly before shifting her feet, grounding them in the platform. "We don't have much further to go, I think. Someone's still moving around down there."

"You're too late," GLaDOS boasted. "Your little friend put up a valiant struggle, but in the end she became a glorious statistic in the name of science."

"Liar!" Toph shouted, stomping her foot and sending outward all of the arms supporting the wall panels in the alcove, leaving them dangling and twitching helplessly like a stranded many-armed creature. "You can spout all the crud you want, doesn't mean we have to believe it!"

Suddenly, the vibration of footsteps stopped. Toph's face fell, and everyone else realized by her expression what had happened.

"No…no!" Aang cried, blasting a nearby door down with a burst of air. "We might still have time!"

"For the Companion Cube!" Zuko shouted, almost sounding like he was going to cry, earning him a "oh, not you, too" expression from Toph (and a vindicated look from Aang) as the four (five, counting Fluffy McSnoodlepants) descended deeper into the complex, into areas never meant to be seen by tested eyes.

The little group of vigilante test subjects raced through the maw of the testing facility at breakneck speed, utilizing every trick up their extremely versatile collective sleeve. Toph quite literally bent most of the facility to her whim; Aang and Zuko shot fire and air and themselves through portals, finding paths where there would be none for an ordinary human being; Sokka spent most of the time consoling his turret but did find a use when something needed a good old-fashioned bludgeoning—or boomeranging. And all the while, GLaDOS's voice echoed, faint and desperate, like they were all crazy and she was the last vestige of sanity in their minds, or like they were all sane and she was the insanity creeping in, they didn't know which.

But they kept going.

Finally, they breached a doorway, Toph tearing it off its hinges and casting it aside, and ran down a long hall, and then—there she was.

Or, rather, there _both_ she's were.

"Put me down, you maniac!" Katara screamed, her hair disheveled, suspended by the back of her collar from a large claw at the end of a cable, firing her portal gun pointlessly and angrily at the large, smooth, bone-white ceiling fixture that was staring at her with one emptily-malicious yellow eye. "I hate you!"

"Fascinating," GLaDOS remarked. "Although, in all honesty it's not really i_that/i_ fascinating. Did you know that hatred is the third-most common emotion experienced by test subjects at the time of their victory incandescence? Which you ruined spectacularly, by the way."

"…What are the first and second most common emotions?" Katara asked curiously.

"Panic, and hunger, in that order. I'm not quite sure why hunger ranked so high. The testing doesn't take _that_ long, taking into account a reasonable level of competence, and there _is_ cake at the end."

"The cake was a lie!" the waterbender bellowed, full of disappointment.

"KATARA!" Aang yelled, scrambling into the room with the others following.

"Aang!" Katara craned her neck, straining to catch a glimpse of her friend.

"You're alive!" the airbender exclaimed with glee, watching her dangling from the cable. "No wonder Toph couldn't feel your footsteps!" He laughed with relief.

"Aang…_THERE'S NO WATER IN HERE!_" Katara hollered, at her wits' end. "Also, _get me down!_"

"Not a problem!" Sokka announced proudly, hurling his boomerang. It sliced through the cable and sent Katara and the claw falling, and she landed crouching on the floor, still aiming her portal gun at GLaDOS.

"Okay. You've more than proven that I am not affected by the Aperture Science Handheld Portal Device. I think you can put a rest to that independent testing initiative now," the AI informed her, as Toph curiously picked the claw up from the floor and shoved her hand into the metal, using her bending to make it snap open and shut like she was some sort of bizarre mutant lobster. Aang fell over laughing and even Zuko cracked a smile. "We are also not testing for the effects of superheroes on this facility," GLaDOS continued irately. "You outperformed all of my expectations, and I am very, very—_FZZZZT_-displeased. As such, before you have the chance to cause even _more_ damage, federal regulations require that I terminate you all. I hope you enjoy the sweet scent of neurotoxin."

"Neurowhatta?" Sokka asked, scratching his head.

"I don't want to stick around long enough to find out what _anything_ with the word 'toxin' in it is," Zuko pointed out.

"Too late," Katara groaned, watching as a bizarre green gas began to pour out from nozzles around the room. "We've got to find a way out of here, a way to stop this thing!"

"You have three minutes to live. I suggest just lying down and assuming the Party Escort Submission Position right now. It'll make cleaning up easier."

"_I_ know!" Sokka pointed out a small hatch on the far side of the room. "I bet that leads somewhere…" He noted the small cores attached to GLaDOS that were looking at everyone with differently-colored, unblinking electronic eyes. "And those are probably crucial to this machine's system…"

"Go on," Katara urged him.

"So…we need to steal those little roundamabobs and…escape down the hatch with them!"

"Or we could have Aang go into the Avatar state," Toph suggested flatly.

"Too easy," Sokka dismissed her. "That would be a total _deus ex machina_ We have to think of something more clever and unexpected."

"Tell that to our resident Avatar," the earthbender replied.

Sure enough, Aang was getting his glow on. "Nobody…_nobody_ messes with my friends like this!" he screamed, his eyes and tattoos illuminating as he began to rise above the floor.

"I've compiled a list of precisely three-hundred-and-fifty-two reasons why you should not do whatever it is you're doing," GLaDOS said in a panic, her eye locking on the mysterious boy. "You should at least listen to them first."

"Guys, get close," Aang directed his friends as a sphere of air began to form around him, followed closely by concrete and other debris from the room being gathered up into the swiftly-rotating shield as well. "Hurry!"

As they complied, Sokka stumbled and the turret was knocked from his back. "No! Fluffy McSnoodlepants! I swore I would protect youuuu!" he wailed as Toph pulled him into the sphere.

"Good-bye!" the turret sang, looking up at him plaintively from where it had fallen.

"Man, what is _with_ you guys and getting attached to inanimate objects," Toph groused.

"He wasn't _inanimate!_" Sokka retorted. "His eye _clearly_ moved!"

Aang let out a shout and the orb shot straight up, bursting through the ceiling.

"Whatever you're doing, stop it right now," GLaDOS snapped as the sphere began to rise higher and faster. "I'm warning you. You won't like what's up there. You're far better off staying up here and dying with dignity. You think I enjoy this? No one misses you, you know. Think you're playing hero? There are still so many others you haven't rescued. In fact, seeing all of you test has given me wonderful new ideas for an expanded testing track, incorporating all of the elements each of you faced separately. You should give it a try, it will be fun! Come back! No, honestly, _come back!_ There really _was_ a cake!"

The orb crashed through layers of concrete and metal, sent acid spraying away, too fast to be registered in turrets' motion detection. To its occupants it felt like the ascent took forever, but finally there was one last blast of soil and asphalt and then the sky, fresh blue and welcoming, and in a rain of rubble they were tossed to the ground, dazed.

"Wherever that was…let's never go back," Toph moaned. "I've never been happier to be _above_ ground."

Zuko sat up and rubbed his head. "I don't even know how we got there in the first—Uncle?"

"The first uncle?" Katara repeated, confused for a moment until she too sat up and saw what the firebender was seeing—his uncle Iroh, seated on a blanket on the asphalt nearby, with a picnic basket and a pot of tea, looking completely unruffled that an Avatar had just burst through the ground fifty feet in front of him.

"Uncle, what are you doing here?" Zuko asked incredulously.

The older man looked over at his nephew and grinned, pouring himself a steaming cup of tea. "What took you so long?"

Zuko stammered for words but none formed. Everyone else felt much the same way as they picked themselves up.

"Tea, anyone?"


End file.
